This is exactly what concerns me about PTC being mandated by a date certain. Is it really perfected and ready for prime time all by itself? Will it prevent a movement from running by a stop signal without unnecessarily taking control of the train out of the hands of the engineer before the train reaches the signal? Existing CSS would probably prevent the vast majority of possible collisions -- and it works. (It also knows which track each train is on.)
However, if the speed had been lower than 15, with the engineer not paying attention, he could still have passed the home signal and collided with the freight train, which had practically reached the interlocking by that time.
You're right it is not as perfect as PTC, but the cost/value ratio is remarkably better. Look at the Northeast commuter operations. Millions of passengers carried every year and not a single fatality due to a passed stop signal in CSS territory. You have a greater chance of being killed by a crazed gunman on the LIRR than you do rolling past a stop signal. PTC is a solution in need of a problem. The irritating part isn't just the cost, its that the whole technology doesn't work very well. The mandate prevents the FRA from adopting flexible regulations that would allow PTC to supplement reliable signaling technologies, but still allow it to be cut out or ignored.
ACSES does pretty much everything they want. It enforces permanent speed restrictions, it enforces temporary speed restrictions, it enforces positive stop signals and it enforces signal speeds. The only thing it does not do is physically stop a train from running into another train that is stopped ahead of it. BUT, since it enforces restricted speed at as little as 15mph. that alone is going to get rid of 98% of collisions. At 15 mph or less, it's pretty hard to not notice another train ahead and apply the brakes. And even if you did not stop in time, just throwing the train in emergency would get you down to a speed that would be at worst, a hard coupling. Likley not hard enough to seriously injure anyone or cause much damage.
If you really look at all the accidents the FRA and NTSB are trying to avoid with PTS, it's stop signal violations. Untill ACSES, nothing was available that could stop a train at a home signal. Cab Signals warn you of a stop signal ahead, but they will not stop you from going by it. ACSES will. ATS will apply the brakes after
you go by the stop signal, by then, it's too late.
And i still have yet to see how PTS will deal with shoving movements. Like ACSES, there is no realistic way to stop a movement from passing a stop signal when the locomotive is not on the leading end.
I really don't see why the government is mandating such an outrageously complicated system. Good training and the right choice of Engineers combined with a system like ACSES is all you need. Just another case of the government trying to overcomplicate everything. What ever happened to just knowing how to do your job? Maybe the real issue is the railroad should start hiring people with a decent level of intelligence and not worry about filling quotas with the right "types" of people. Hire the best PEOPLE for the job and give them the proper training. It's scary that the quality of training is going down and the character of people being hired is as well. Not good.